538 ANNUAL RECORD OF SCIENCE AND INDUSTRY.' 



the tendency to decomposition of the solution by action of 

 the electric current. These various organic acid salts may 

 be added interchangeably and collectively, though the in- 

 ventor prefers to use, in case of the double salts of nickel and 

 alkalies and alkaline earths, the organic acid salts which have 

 for their bases the alkali or alkaline earth which is associated 

 with the nickel in its double salt. Thus when using a solu- 

 tion of nickel and ammonia, an organic acid salt of ammonia 

 is preferred, though the similar salts of soda and potash will 

 answer very well. In case of using a solution of a double 

 salt of nickel and potash, or a double salt of nickel and soda, 

 an organic acid salt of soda and potash is selected. Of the 

 salts which can be used to accomplish the effect the tartrates 

 are preferable. A comparatively small quantity of the or- 

 ganic salts is necessary to be added, though it will not change 

 the character of the deposit. 



The following bath is said to work well : To twenty gal- 

 lons of a solution in water of the double sulphate of nickel 

 and ammonia, of 7 Baume, add one gallon of a solution, of 

 an equal gravity, of neutral tartrate of ammonia in water. 

 Mix well, and the bath will be ready after standing a few 

 hours. 16 A, July, 1872, 402. 



OBJECTION TO USING GLYCERINE AS A PRESERVATIVE. 



The use of glycerine as a preservative of anatomical ob- 

 jects, or specimens of natural history, has been strongly rec- 

 ommended ; but it appears from experiments that it has an 

 unfavorable action upon certain tissues. Thus, teeth kept 

 for some time in glycerine lose their original hardness, and 

 can be cut with a knife like horn, and oxalate of lime crystals 

 appear to be completely broken up. These hints will be of 

 importance to those who are in the habit of making wet prep- 

 arations with this substance. 3 A, January 13, 1872, 26. 



EMBALMING AMONG THE EGYPTIANS. 



Dr. Benjamin W. Richardson, in a lecture upon the science 

 and art of embalming the dead, remarks that three different 

 methods were practiced among the Egyptians. First, em- 

 balming proper, by the introduction into the body of certain 

 odorous essences or antiseptics, aided by after-immersion in 

 saline solutions ; second, preservation by simple extraction of 



